Jeep 1997 Grand Cherokee Service Manual page 354

CLOCKWISE ROTATION 1 5 3 6 2 4 FIRING ORDER: OF ENGINE FRONT CABLE SPARK BOOT PLUG AND CLOCKWISE ROTATION SPARK PLUG 1-8-4-3-6-5-7-2
8D - 12 IGNITION SYSTEM
REMOVAL AND INSTALLATION (Continued)
Fig. 22 Cable Removal
Fig. 23 Engine Firing Order—4.0L 6–Cyl.Engine
Fig. 24 Engine Firing Order—5.2L/5.9LV-8 Engines
SPARK PLUG BOOT FRONT TWIST AND PULL PULLER AIR GAP SPARK PLUG HEAT SHIELD BOOT
SPARK PLUGS
On 5.2L/5.9L V-8 engines, spark plug cable heat
shields are pressed into the cylinder head to sur-
round each cable boot and spark plug (Fig. 25).
Fig. 25 Heat Shields—5.2L/5.9LEngines
If removal of the heat shield(s) is necessary,
remove the spark plug cable and compress the sides
of shield for removal. Each shield is slotted to allow
for compression and removal. To install the shields,
align shield to machined opening in cylinder head
and tap into place with a block of wood.
PLUG REMOVAL
(1) Always remove spark plug or ignition coil
cables by grasping at the cable boot (Fig. 22). Turn
the cable boot 1/2 turn and pull straight back in a
steady motion. Never pull directly on the cable.
Internal damage to cable will result.
(2) Prior to removing the spark plug, spray com-
pressed air around the spark plug hole and the area
around the spark plug. This will help prevent foreign
material from entering the combustion chamber.
(3) Remove the spark plug using a quality socket
with a rubber or foam insert.
(4) Inspect the spark plug condition. Refer to
Spark Plug Condition in the Diagnostics and Testing
section of this group.
PLUG CLEANING
The plugs may be cleaned using commercially
available spark plug cleaning equipment. After clean-
ing, file the center electrode flat with a small point
file or jewelers file before adjusting gap.
CAUTION: Never use a motorized wire wheel brush
to clean the spark plugs. Metallic deposits will
remain on the spark plug insulator and will cause
plug misfire.
ZG